The present disclosure relates to heat exchangers, and in particular to curved plate-fin heat exchangers.
Heat exchangers are often used to transfer heat between two fluids. For example, in aircraft environmental control systems, heat exchangers may be used to transfer heat between a relatively hot air source (e.g., bleed air from a gas turbine engine) and a relatively cool air source (e.g., ram air). Some heat exchangers, often referred to as plate-fin heat exchangers, include a plate-fin core having multiple heat transfer sheets arranged in layers to define air passages there between. Closure bars seal alternating inlets of hot air and cool air inlet sides of the core. Accordingly, hot air and cool air are directed through alternating passages to form alternating layers of hot and cool air within the core. Heat is transferred between the hot and cool air via the heat transfer sheets that separate the layers. In addition, to facilitate heat transfer between the layers, each of the passages can include heat transfer fins, often formed of corrugated material (e.g., aluminum), that are oriented in a direction of the flow within the passage. The heat transfer fins increase turbulence and a surface area that is exposed to the airflow, thereby enhancing heat transfer between the layers.
Due to existing corrugated sheet structures and manufacturing techniques, known plate-fin heat exchangers have a rectangular axial cross section. In some applications, such as aircraft environmental control systems, the plate-fin heat exchangers are arranged around a central axis. As a result of the rectangular cross section of the plate-fin heat exchangers, gaps occur between adjacent plate-fin heat exchangers and between a curved housing and the plate-fin heat exchangers when the plate-fin heat exchangers are arranged circumferentially about the central axis. These gaps creates dead space next to the plate-fin heat exchangers that cannot be used by the plate-fin heat exchangers.